Build scalable backend systems, APIs, data pipelines, and DevOps practices using Python or full-stack JavaScript, integrating voice, reasoning, and context management. You will ship end-to-end product features for an AI layer designed to autonomously run small businesses for thousands of customers.

You will work with React, React Native, Node.js, TypeScript, SQL, AWS, and cloud-native AI-powered products. The company is a Series A–funded, fast-growing tech business building products that matter and planning to double in size. This Staff Engineer role owns business-critical product areas and mentors engineers while remaining deeply hands-on.

Join a pre-seed voice AI startup as a Junior Fullstack Engineer, working with Python, AWS, and Kubernetes to build integrations, API fixes, and SDKs for enterprise clients. You'll support the Forward Deployed Engineering team deploying voice infrastructure across Africa and the Middle East.

Python, FastAPI, TypeScript, React, and GCP. Electric Twin builds a behavioral simulation platform that creates digital twins of populations to predict human behavior. You will join a team of 17.

Build and deploy production-grade agentic systems and RAG pipelines with Python, TypeScript, FastAPI, and React. As a founding engineer, lead architectural development of an AI-driven agency model replacing traditional property-market manual workflows with autonomous agents.

You will use Python, FastAPI, and advanced LLM techniques including chain-of-thought, RAG, and multi-agent tool use to build cognitive architectures for synthetic populations. Working within Electric Twin's Science team, you will design memory systems and decision-making frameworks that simulate human responses for behavioral prediction.

As a founding AI engineer, you’ll build production algorithms and evaluation pipelines using Python, LLMs, prompt engineering, OpenAI evals, PostgreSQL, and React/TypeScript. You will develop AI for patent generation, pushing LLM boundaries to boost efficiency for 400+ global IP teams. You work directly with PhD founders from UCL and Cambridge.

Work with JavaScript, Vue.js/React/Angular, HTML/CSS, and Figma to build scalable UI components. Join TransPerfect’s TechOps team, which delivers technology and interfaces for the company’s GlobalLink platform.

You will work with Java 17+, Spring Boot, Oracle SQL, document store DBs, Kubernetes, Jenkins, and GitHub Copilot. The investment bank team builds mission-critical, high-performance systems providing end-to-end visibility into payment lifecycles for technical, operations, and reporting teams.

Develop features across Vue.js, .NET, and AWS for VIDA, an AI-powered platform reducing musculoskeletal pain. You'll ship end-to-end features using Vue.js and .NET Core, including natural language AI analysis tools, and collaborate with clinical experts and UX designers.

All Your BI★5.0 (5)· London

You will lead All Your BI's AI/GenAI work, setting technical direction for architecture, build-vs-buy, and production-grade LLM applications, RAG, agents, and tool-calling. You'll use Python, modern AI stack (Anthropic/OpenAI/open models, vector databases, orchestration), and LLMOps (evals, observability, guardrails). The team is a self-organizing, Holacracy-based data agency of 60+ people delivering managed BI services for logistics and industrial companies.

Work with Cypress, Playwright, Selenium, Appium, Postman, Jira, and Git to build and maintain automated test suites integrated into a CI/CD pipeline. As part of Reset Health's QA team, you will design manual and automated tests for web and native mobile apps while helping transition to greater automation and AI under an ISO13485 QMS.

Fintricity★1.0 (1)· London

You will work with Python, TypeScript, LLMs, agent frameworks, RAG systems, vector databases, LangGraph, LangChain, and cloud services. The role builds enterprise-grade AI infrastructure for agentic systems, including AI gateways, model orchestration, and agent control planes at Fintricity and Kendra Labs.

Luxoft★4.5 (669)· London

You'll build an investment-insights solution using Agentic AI, working with Python, FastAPI, AWS, Git/CI/CD, vector databases, RAG patterns, and LLMs like OpenAI/Anthropic. The project generates investment insights from sales and research materials to speed client-meeting preparation. Nice-to-have skills include React/TypeScript and AgentCore, but team size is unstated.

NatWest Group★3.7 (1.2k)· London

You will work with React, Java, Spring Boot, REST APIs, Kafka, IBM MQ, iOS, and Android, applying test-driven development and Agile practices. As a member of a permanent feature team, you will design, develop, and test software for the bank’s platform, collaborating with engineers and architects.

Design software using Java, C#, Python, JavaScript, TypeScript, or Go, with REST APIs, microservices, SQL databases (PostgreSQL, SQL Server, MySQL, Oracle, MongoDB), and cloud platforms (AWS, Azure, GCP). You will build enterprise applications and business-critical services across the full development lifecycle.

Develop mobile apps in React Native (iOS/Android) with TypeScript, Expo, and Jest, integrating with Ruby on Rails backend services over a JSON API and Postgres. You will join the product team building a market-leading platform that manages the end-to-end installation of home energy solutions like boilers, heat pumps, and solar panels for brands such as BOXT and E.ON Next.

Bionic Group★2.9 (27)· London

You will work with Node.js/TypeScript, Ruby/Rails, Nuxt, AWS CDK, and Salesforce, building backend services and customer-facing frontend applications. As part of Bionic’s “In Life” squad, you’ll help improve Digital Renewals customer journeys for their SME business comparison and switching service.

NatWest Group★3.7 (1.2k)· London

Working with JavaScript, ReactJS, AngularJS, Python, Java, Microsoft Dynamics, AWS, GitLab, Google Cloud Platform, Kafka, Hadoop, PostgreSQL, and Snowflake, you’ll join the Engineering Platforms team to deliver a modern software development toolchain for engineers across the bank.

Genpact★3.8 (7.9k)· London

Develop, test, and debug Java-based software applications using Agile methodology, Apache Kafka, and Java full-stack development. You will collaborate with teams to enhance application performance and optimize code for scalability. Genpact is an agentic and advanced technology solutions company leveraging process intelligence and AI.

You will work with AWS (WAF, CloudFront, CloudTrail, GuardDuty, Secrets Manager), WorkOS/AuthKit, and CI dependency-audit tools. The team builds Palette, an urban-planning platform for biodiversity and resilience gain, owned by Kew Reach (a joint venture with Royal Botanic Gardens Kew). This is a founding sole platform-engineer role, reporting to the CEO.

A full-stack engineer at an AI-powered insurance platform, working in TypeScript, Python, and AWS. You will build and debug production code across the stack, integrating APIs and configuring partner insurance offerings. You will be one of the first UK engineering hires, working hands-on with a small team to extend the platform and keep integrations live.

Founding Engineer role at a London AI startup building an agentic platform for civil engineering. You’ll work with Python, GCP (Cloud Run, Pub/Sub, Postgres), React, Terraform, and LLM techniques like RAG and MCP, owning backend architecture and AI integration directly with the CTO.

You'll work with Python, modern ML tooling, LLMs, and simulations, owning the AI/ML stack including model selection, fine-tuning, and inference infrastructure. Prior Foundry builds specialized AI agents and inference systems to solve complex global policy problems for the public sector in social science and public policy.

Work with Svelte/TypeScript, Python (FastAPI, Django), PostgreSQL, and AWS. Tab is a YC-backed London travel fintech building a payments platform for 100,000+ global tourism businesses, processing thousands of real-time transactions per hour. You will develop features across the stack and collaborate in a tight-knit engineering team.